DOCSLIB.ORG

Biodiversity Series Background Document for Basking Shark

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Background Document for Basking shark Cetorhinus maximus Biodiversity Series 2009 OSPAR Convention Convention OSPAR The Convention for the Protection of the La Convention pour la protection du milieu Marine Environment of the North-East Atlantic marin de l'Atlantique du Nord-Est, dite (the “OSPAR Convention”) was opened for Convention OSPAR, a été ouverte à la signature at the Ministerial Meeting of the signature à la réunion ministérielle des former Oslo and Paris Commissions in Paris anciennes Commissions d'Oslo et de Paris, on 22 September 1992. The Convention à Paris le 22 septembre 1992. La Convention entered into force on 25 March 1998. It has est entrée en vigueur le 25 mars 1998. been ratified by Belgium, Denmark, Finland, La Convention a été ratifiée par l'Allemagne, France, Germany, Iceland, Ireland, la Belgique, le Danemark, la Finlande, Luxembourg, Netherlands, Norway, Portugal, la France, l’Irlande, l’Islande, le Luxembourg, Sweden, Switzerland and the United Kingdom la Norvège, les Pays-Bas, le Portugal, and approved by the European Community le Royaume-Uni de Grande Bretagne and Spain. et d’Irlande du Nord, la Suède et la Suisse et approuvée par la Communauté européenne et l’Espagne. Acknowledgement This report has been prepared by the Association pour l'Etude et la Conservation des Sélaciens (APECS) and Ms Amelia Curd (France). Thanks are also due for contributions provided by Colin Speedie, Sarah Fowler, David Sims, Jean-Luc Solandt Photo acknowledgement: Cover page: Basking shark, wikipedia Contents Background Document for Basking shark Cetorhinus maximus .....................................................3 Executive Summary ...........................................................................................................................3 Récapitulatif .......................................................................................................................................3 1. Background Information...............................................................................................................4 Name of species (feature) ...........................................................................................................4 2. Original Evaluation against the Texel-Faial selection criteria......................................................4 List of OSPAR Regions and Dinter biogeographic zones where the species occurs .................4 List of OSPAR Regions and Dinter biogeographic zones where the species is under threat and/or in decline ................................................................................................................4 Original evaluation against the Texel-Faial criteria for which the species was included on the OSPAR List ......................................................................................................................4 3. Current status of the species or habitat.......................................................................................5 Distribution in OSPAR maritime area ..........................................................................................5 Population (current/trends/future prospects) ...............................................................................6 Condition (current/trends/future prospects).................................................................................6 Limitations in knowledge ...........................................................................................................11 4. Evaluation of threats and impacts .............................................................................................11 Fishing .......................................................................................................................................11 Human Impacts..........................................................................................................................12 Climate change..........................................................................................................................12 5. Existing Management measures ...............................................................................................12 6. Conclusion on overall status......................................................................................................14 7. Action to be taken by OSPAR? .................................................................................................15 Action/measures that OSPAR could take, subject to OSPAR agreement ................................15 Brief summary of the proposed monitoring system (see annex 2)............................................18 Annex 1: Overview of data and information provided by Contracting Parties ..............................19 Summaries of country-specific information provided.......................................................................21 Annex 2: Detailed description of the proposed monitoring and assessment strategy ................22 Rationale for the proposed monitoring.............................................................................................22 Use of existing monitoring programmes ..........................................................................................22 Synergies with monitoring of other species or habitats ...................................................................23 Assessment criteria..........................................................................................................................23 Techniques/approaches...................................................................................................................23 Selection of monitoring locations .....................................................................................................24 Timing and Frequency of monitoring. ..............................................................................................24 Data collection and reporting ...........................................................................................................24 Quality assurance ............................................................................................................................24 Annex 3: References............................................................................................................................25 Annex 4: Biological and Historical Fishing Background Information ............................................28 Biological Background Information ..................................................................................................28 Historical Fishing Background Information ......................................................................................31 2 OSPAR Commission 2009 Background Document for Basking shark Cetorhinus maximus (Martin R.A. & Harvey-Clark, 2004) Executive Summary This Background Document for Basking shark – Cetorhinus maximus – has been developed by OSPAR following the inclusion of this species on the OSPAR List of threatened and/or declining species and habitats (OSPAR Agreement 2008-6). The document provides a compilation of the reviews and assessments that have been prepared concerning this species since the agreement to include it in the OSPAR List in 2003. The original evaluation used to justify the inclusion of Cetorhinus maximus in the OSPAR List is followed by an assessment of the most recent information on its status (distribution, population, condition) and key threats prepared during 2009-2010. Chapter 7 provides proposals for the actions and measures that could be taken to improve the conservation status of the species. In agreeing to the publication of this document, Contracting Parties have indicated the need to further review these proposals. Publication of this background document does not, therefore, imply any formal endorsement of these proposals by the OSPAR Commission. On the basis of the further review of these proposals, OSPAR will continue its work to ensure the protection of Cetorhinus maximus, where necessary in cooperation with other competent organisations. This background document may be updated to reflect further developments or further information on the status of the species which becomes available. Récapitulatif Le présent document de fond sur le requin pèlerin a été élaboré par OSPAR à la suite de l’inclusion de cette espèce dans la liste OSPAR des espèces et habitats menacés et/ou en déclin (Accord OSPAR 2008-6). Ce document comporte une compilation des revues et des évaluations concernant cette espèce qui ont été préparées depuis qu’il a été convenu de l’inclure dans la Liste OSPAR en 2003. L’évaluation d’origine permettant de justifier l’inclusion du requin pèlerin dans la Liste OSPAR est suivie d’une évaluation des informations les plus récentes sur son statut (distribution, population, condition) et des menaces clés, préparée en 2009-2010. Le chapitre 7 fournit des propositions d’actions et de mesures qui pourraient être prises afin d’améliorer l’état de conservation de l’espèce. En se mettant d’accord sur la publication de ce document, les Parties contractantes ont indiqué la nécessité de réviser de nouveau ces propositions. La publication de ce document ne signifie pas, par conséquent que la Commission OSPAR entérine ces propositions de manière formelle. A partir de la nouvelle révision de ces propositions, OSPAR poursuivra ses travaux afin de s’assurer de la protection du requin pèlerin, le cas échéant avec la coopération d’autres organisations compétentes.
Recommended publications
  • Lévy Flights and the Search Behaviour of Marine Top Predators

    Lévy Flights and the Search Behaviour of Marine Top Predators

    Lévy flights and the search behaviour of marine top predators David Sims Marine Biological Association Laboratory, Plymouth, UK & Biological Sciences, University of Plymouth, UK Royal Society, 2006 Collaborators Julian Metcalfe, David Righton (Cefas, Lowestoft) Graeme Hays, Rory Wilson (University of Wales Swansea) David Morritt (U. London) MBA Behavioural Ecology Research Group Corey Bradshaw (Adelaide, Australia) Leader: David Sims Anthony Richardson (U. Queensland, Australia) Emily Southall, Viki Wearmouth, Steve Cotterell, Nick Mohammed Z. Ahmed (U. Plymouth) Humphries, Andrew Griffiths, Matt McHugh, Josh Filer, Andy Brierley (U. St Andrews) Jenny Dyer, Joel Kimber, Nuno Queiroz, Nick Pade, Jon Pitchford (U. York), Alex James (U. Canterbury, NZ) Chrysoula Gubili, Tristan Guttridge, Edd Brooks (in Mike Musyl (U. Hawaii, USA), Kurt Schaefer (IATTC La Jolla) Bahamas), Zoe Brooke, John Rundle, Pete Rendle Mark Hindell (U. Tasmania), John Stevens (CSIRO, Hobart) & EUTOPIA partners Biological search problem How to find objects at unknown locations For hunters - what search strategy to employ: • To maximise likelihood of encounter rate • In environments that are complex, heterogeneous • With incomplete knowledge Deterministic - probabilistic Fine-scale clues… Video clip: Owen Bruce, Save Our Seas Foundation Geographical scale… Mucientes et al, & Sims (2009) Biol. Lett. 5, 156-159 See Nature Research Highlights 0.5 m SearchSearch decisionsdecisions Movements ?? Resource time Empirical Approach Fully aquatic marine predators are useful model
  • Can Threshold Foraging Responses of Basking Sharks Be Used to Estimate Their Metabolic Rate?

    Can Threshold Foraging Responses of Basking Sharks Be Used to Estimate Their Metabolic Rate?

    MARINE ECOLOGY PROGRESS SERIES Vol. 200: 289-296,2000 Published July 14 Mar Ecol Prog Ser ~ NOTE Can threshold foraging responses of basking sharks be used to estimate their metabolic rate? David W. Sims* Department of Zoology, University of Aberdeen. Tillydrone Avenue. Aberdeen AB24 2TZ. United Kingdom ABSTRACT: Empirical and theoretical determinations of There are 3 species of filter-feeding shark, the whale minimum threshold prey densities for filter-feeding basking shark ~hi~~~d~~typus of warm-temperate and tropical sharks Cetorhinus maximus were used to test the idea that threshold foraging behaviour could provide a means for esti- seas worldwide, the basking shark Cetorhinus max- mating oxygen consumption (a proxy for metabolic rate). The im~~that inhabits warm-temperate to boreal waters threshold feeding levelrepres&nts the prey density at which circumglobally, and the megamouth shark Mega- there will be no net energy gain (energy intake equals expen- chasms pelagjos occurs in the Pacific and At- diture). Basking sharks were observed to cease feeding at lantic, primarily in deep water (Compagno 1984, Yano their theoretical threshold; thus, the assumption underpin- ning the concept presented here was that over the narrow et They are the largest marine verte- range of zooplankton prey densities that induce 'switching' brates attaining body lengths of up to 14, 10 and 6 m re- between feeding and non-feeding in basking sharks, the spectively. Comparatively little is known about the bi- energetic value of the minimum threshold prey density is ology of planktivorous sharks despite the fact that they equivalent to the shark's instantaneous level of energy expen- diture.
  • Lamna Nasus) Inferred from a Data Mining in the Spanish Longline Fishery Targeting Swordfish (Xiphias Gladius) in the Atlantic for the 1987-2017 Period

    Lamna Nasus) Inferred from a Data Mining in the Spanish Longline Fishery Targeting Swordfish (Xiphias Gladius) in the Atlantic for the 1987-2017 Period

    SCRS/2020/073 Collect. Vol. Sci. Pap. ICCAT, 77(6): 89-117 (2020) SIZE AND AREA DISTRIBUTION OF PORBEAGLE (LAMNA NASUS) INFERRED FROM A DATA MINING IN THE SPANISH LONGLINE FISHERY TARGETING SWORDFISH (XIPHIAS GLADIUS) IN THE ATLANTIC FOR THE 1987-2017 PERIOD J. Mejuto1, A. Ramos-Cartelle1, B. García-Cortés1 and J. Fernández-Costa1 SUMMARY A total of 5,136 size observations of porbeagle were recovered for the period 1987-2017. The GLM results explained very moderately the variability of the sizes considering three main factors, suggesting minor but significant differences in some cases especially for the year factor and non-significant differences in other factors depending on the analysis. The greatest differences in the standardized mean length between some zones were caused by some large fish of unidentified sex. The standardized mean length data for the northern zones showed stability throughout the time series, very stable range of mean values and very few differences between sexes. The size distribution for northern areas indicated an FL-overall mean of 158 cm. The size showed a normal distribution confirming that a small fraction of individuals of this stock/s is available in the oceanic areas where the North Atlantic fleet is regularly fishing and the fishes are not fully recruited to those areas and / or this fishing gear up to 160 cm. The data suggests that some individuals could sporadically reach some intertropical areas of the eastern Atlantic. RÉSUMÉ Un total de 5.136 observations de taille de requins-taupes communs ont été récupérées pour la période 1987-2017. Les résultats du GLM expliquent très modérément la variabilité des tailles en tenant compte de trois facteurs principaux, ce qui suggère des différences mineures mais significatives dans certains cas, notamment pour le facteur année et des différences non significatives pour d'autres facteurs selon le type d’analyse.
  • Electrosensory Pore Distribution and Feeding in the Basking Shark Cetorhinus Maximus (Lamniformes: Cetorhinidae)

    Electrosensory Pore Distribution and Feeding in the Basking Shark Cetorhinus Maximus (Lamniformes: Cetorhinidae)

    Vol. 12: 33–36, 2011 AQUATIC BIOLOGY Published online March 3 doi: 10.3354/ab00328 Aquat Biol NOTE Electrosensory pore distribution and feeding in the basking shark Cetorhinus maximus (Lamniformes: Cetorhinidae) Ryan M. Kempster*, Shaun P. Collin The UWA Oceans Institute and the School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia ABSTRACT: The basking shark Cetorhinus maximus is the second largest fish in the world, attaining lengths of up to 10 m. Very little is known of its sensory biology, particularly in relation to its feeding behaviour. We describe the abundance and distribution of ampullary pores over the head and pro- pose that both the spacing and orientation of electrosensory pores enables C. maximus to use passive electroreception to track the diel vertical migrations of zooplankton that enable the shark to meet the energetic costs of ram filter feeding. KEY WORDS: Ampullae of Lorenzini · Electroreception · Filter feeding · Basking shark Resale or republication not permitted without written consent of the publisher INTRODUCTION shark Rhincodon typus and the megamouth shark Megachasma pelagios, which can attain lengths of up Electroreception is an ancient sensory modality that to 14 and 6 m, respectively (Compagno 1984). These 3 has evolved independently across the animal kingdom filter-feeding sharks are among the largest living in multiple groups (Scheich et al. 1986, Collin & White- marine vertebrates (Compagno 1984) and yet they are head 2004). Repeated independent evolution of elec- all able to meet their energetic costs through the con- troreception emphasises the importance of this sense sumption of tiny zooplankton.
  • Order LAMNIFORMES ODONTASPIDIDAE Sand Tiger Sharks Iagnostic Characters: Large Sharks

    Order LAMNIFORMES ODONTASPIDIDAE Sand Tiger Sharks Iagnostic Characters: Large Sharks

    click for previous page Lamniformes: Odontaspididae 419 Order LAMNIFORMES ODONTASPIDIDAE Sand tiger sharks iagnostic characters: Large sharks. Head with 5 medium-sized gill slits, all in front of pectoral-fin bases, Dtheir upper ends not extending onto dorsal surface of head; eyes small or moderately large, with- out nictitating eyelids; no nasal barbels or nasoral grooves; snout conical or moderately depressed, not blade-like;mouth very long and angular, extending well behind eyes when jaws are not protruded;lower labial furrows present at mouth corners; anterior teeth enlarged, with long, narrow, sharp-edged but unserrated cusps and small basal cusplets (absent in young of at least 1 species), the upper anteriors separated from the laterals by a gap and tiny intermediate teeth; gill arches without rakers; spiracles present but very small. Two moderately large high dorsal fins, the first dorsal fin originating well in advance of the pelvic fins, the second dorsal fin as large as or somewhat smaller than the first dorsal fin;anal fin as large as second dorsal fin or slightly smaller; caudal fin short, asymmetrical, with a strong subterminal notch and a short but well marked ventral lobe. Caudal peduncle not depressed, without keels; a deep upper precaudal pit present but no lower pit. Intestinal valve of ring type, with turns closely packed like a stack of washers. Colour: grey or grey-brown to blackish above, blackish to light grey or white, with round or oval dark spots and blotches vari- ably present on 2 species. high dorsal fins upper precaudal eyes without pit present nictitating eyelids intestinal valve of ring type Habitat, biology, and fisheries: Wide-ranging, tropical to cool-temperate sharks, found inshore and down to moderate depths on the edge of the continental shelves and around some oceanic islands, and in the open ocean.
  • The Denticle Surface of Thresher Shark Tails: Three-Dimensional Structure and Comparison to Other Pelagic Species

    The Denticle Surface of Thresher Shark Tails: Three-Dimensional Structure and Comparison to Other Pelagic Species

    Received: 3 April 2020 Revised: 14 May 2020 Accepted: 21 May 2020 DOI: 10.1002/jmor.21222 RESEARCH ARTICLE The denticle surface of thresher shark tails: Three-dimensional structure and comparison to other pelagic species Meagan Popp1 | Connor F. White1 | Diego Bernal2 | Dylan K. Wainwright1 | George V. Lauder1 1Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Abstract Massachusetts Shark skin denticles (scales) are diverse in morphology both among species and 2 Department of Biology, University of across the body of single individuals, although the function of this diversity is poorly Massachusetts Dartmouth, Dartmouth, Massachusetts understood. The extremely elongate and highly flexible tail of thresher sharks pro- vides an opportunity to characterize gradients in denticle surface characteristics Correspondence George V. Lauder, Museum of Comparative along the length of the tail and assess correlations between denticle morphology and Zoology, 26 Oxford Street, Cambridge, MA tail kinematics. We measured denticle morphology on the caudal fin of three mature 02138. Email: [email protected] and two embryo common thresher sharks (Alopias vulpinus), and we compared thresher tail denticles to those of eleven other shark species. Using surface Funding information National Oceanic and Atmospheric profilometry, we quantified 3D-denticle patterning and texture along the tail of Administration, Grant/Award Number: threshers (27 regions in adults, and 16 regions in embryos). We report that tails of NA16NMF4270231; National Science Foundation, Grant/Award Numbers: IOS- thresher embryos have a membrane that covers the denticles and reduces surface 1354593, GRF DGE-1144152; Office of Naval roughness. In mature thresher tails, surfaces have an average roughness of 5.6 μm Research, Grant/Award Numbers: N00014-09-1-0352, N000141410533 which is smoother than some other pelagic shark species, but similar in roughness to blacktip, porbeagle, and bonnethead shark tails.
  • Porbeagle Shark Lamna Nasus

    Porbeagle Shark Lamna Nasus

    Porbeagle Shark Lamna nasus Lateral View (♀) Ventral View (♀) COMMON NAMES APPEARANCE Porbeagle Shark, Atlantic Mackerel Shark, Blue Dog, Bottle-nosed • Heavily built but streamlined mackerel shark. Shark, Beaumaris Shark, Requin-Taupe Commun (Fr), Marrajo • Moderately long conical snout with a relatively large eyes. Sardinero (Es), Tiburón Sardinero (Es), Tintorera (Es). • Large first dorsal fin with a conspicuous white free rear tip. SYNONYMS • Second dorsal fin and anal fin equal-sized and set together. Squalus glaucus (Gunnerus, 1758), Squalus cornubicus (Gmelin, 1789), • Lunate caudal fin with strong keel and small secondary keel. Squalus pennanti (Walbaum, 1792), Lamna pennanti (Desvaux, 1851), Squalus monensis (Shaw, 1804), Squalus cornubiensis (Pennant, 1812), • Dorsally dark blue to grey with no patterning. Squalus selanonus (Walker, 1818), Selanonius walkeri (Fleming, 1828), • Ventrally white. Lamna punctata (Storer, 1839), Oxyrhina daekyi (Gill, 1862), Lamna • Maximum length of 365cm, though rarely to this size. NE MED ATL philippi (Perez Canto, 1886), Lamna whitleyi (Phillipps, 1935). DISTRIBUTION The Porbeagle Shark is a large, streamlined mackerel shark with a In the northern conical snout and powerful body. The first dorsal fin is large and hemisphere, the originates above or slightly behind the pectoral fins. It has a free rear Porbeagle Shark tip which is white. The second dorsal fin is tiny and is set above the occurs only in the anal fin, to which it is comparable in size. The caudal fin is strong and North Atlantic and lunate with a small terminal notch. The caudal keel is strong and, Mediterranean, uniquely for the northeast Atlantic, a smaller secondary caudal keel is whilst in the present.
  • Can Sharks Be Saved? a Global Plan of Action for Shark Conservation in the Regime of the Convention on Migratory Species

    Can Sharks Be Saved? a Global Plan of Action for Shark Conservation in the Regime of the Convention on Migratory Species

    Seattle Journal of Environmental Law Volume 5 Issue 1 Article 15 5-31-2015 Can Sharks be Saved? A Global Plan of Action for Shark Conservation in the Regime of the Convention on Migratory Species James Kraska Leo Chan Gaskins Follow this and additional works at: https://digitalcommons.law.seattleu.edu/sjel Part of the Education Commons, Environmental Law Commons, Intellectual Property Law Commons, Internet Law Commons, Land Use Law Commons, Natural Resources Law Commons, Science and Technology Law Commons, and the Water Law Commons Recommended Citation Kraska, James and Gaskins, Leo Chan (2015) "Can Sharks be Saved? A Global Plan of Action for Shark Conservation in the Regime of the Convention on Migratory Species," Seattle Journal of Environmental Law: Vol. 5 : Iss. 1 , Article 15. Available at: https://digitalcommons.law.seattleu.edu/sjel/vol5/iss1/15 This Article is brought to you for free and open access by the Student Publications and Programs at Seattle University School of Law Digital Commons. It has been accepted for inclusion in Seattle Journal of Environmental Law by an authorized editor of Seattle University School of Law Digital Commons. Can Sharks be Saved? A Global Plan of Action for Shark Conservation in the Regime of the Convention on Migratory Species James Kraska† and Leo Chan Gaskins‡ Shark populations throughout the world are at grave risk; some spe- cies have declined by 95 percent. The most recent IUCN (Interna- tional Union for the Conservation of Nature) assessment by the Shark Specialist Group (SSG) found that one-fourth of shark and ray spe- cies face the prospect of extinction.
  • Coelho Phd Lantern S

    Coelho Phd Lantern S

    UNIVERSIDADEdo ALGARVE FaculdadedeCiênciasdoMaredo Ambiente Biology,populationdynamics,managementandconservation ofdeepwaterlanternsharks,Etmopterusspinax and Etmopteruspusillus (Chondrichthyes:Etmopteridae)insouthernPortugal(northeastAtlantic). (DoutoramentoemCiênciaseTecnologiasdasPescas,especialidadedeBiologiaPesqueira) (ThesisforthedegreeinDoctorofPhilosophyinFisheriesSciencesandTechnologies,specialtyinFisheriesBiology) RUIPEDROANDRADECOELHO Faro (2007) UNIVERSIDADE DO ALGARVE FACULDADE DE CIÊNCIAS DO MAR E DO AMBIENTE Biology, population dynamics, management and conservation of deep water lantern sharks, Etmopterus spinax and Etmopterus pusillus (Chondrichthyes: Etmopteridae) in southern Portugal (northeast Atlantic). (Doutoramento em Ciências e Tecnologias das Pescas, especialidade de Biologia Pesqueira) (Thesis for the degree in Doctor of Philosophy in Fisheries Sciences and Technologies, specialty in Fisheries Biology) RUI PEDRO ANDRADE COELHO Orientador / Supervisor: Prof. Doutor Karim Erzini Júri / Jury: - Prof. Doutor José Pedro Andrade, Professor Catedrático da Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve; - Prof. Doutor Karim Erzini, Professor Associado com Agregação da Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve; - Prof. Doutor Leonel Paulo Sul de Serrano Gordo, Professor Auxiliar com Agregação da Faculdade de Ciências, Universidade de Lisboa; - Prof. Doutor Manuel Seixas Afonso Dias, Professor Auxiliar da Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve;
  • The Kerguelen Plateau: Marine Ecosystem + Fisheries

    The Kerguelen Plateau: Marine Ecosystem + Fisheries

    THE KERGUELEN PLATEAU: MARINE ECOSYSTEM + FISHERIES Proceedings of the Second Symposium Kerguelen plateau Marine Ecosystems & Fisheries • SYMPOSIUM 2017 heardisland.antarctica.gov.au/research/kerguelen-plateau-symposium Shark by-catch observed in the bottom longline fishery off the Kerguelen Islands in 2006–2016, with a focus on the traveller lantern shark (Etmopterus viator) Charlotte Chazeau1, Samuel P. Iglésias2, Clara Péron1, Nicolas Gasco1, Alexis Martin1 and Guy Duhamel1 1 Muséum national d’Histoire naturelle, Département Adaptations du vivant, UMR 7208 BOREA (MNHN, CNRS, IRD, Sorbonne Université, UCBN), CP 26, 43 rue Cuvier, 75231 Paris Cedex 05, France 2 Institut Systématique Evolution Biodiversité (ISYEB), Muséum national d’Histoire naturelle, CNRS, Sorbonne Université, Station Marine de Concarneau, Place de la Croix, 29900 Concarneau, France Corresponding author: [email protected] Abstract Data collected by fishery observers on board French fishing vessels targeting Patagonian toothfish (Dissostichus eleginoides), were examined to quantify and describe shark by-catch within the Kerguelen exclusive economic zone (EEZ). From 2006 to 2016, the fishing crews of longline vessels reported the total catches of the line and observers were asked to identify and count fish by-catch on 25% of the total fishing effort. A total of 26 203 longline hauls and more than 55 million hooks were checked by observers reporting 29 500 individual sharks caught as by-catch. Four shark species were identified (traveller lantern shark – Etmopterus viator, southern sleeper shark – Somniosus antarcticus, Portuguese dogfish – Centroscymnus coelolepis and porbeagle shark – Lamna nasus) among which E. viator was numerically largely dominant (99%). Relative abundance (number of shark per 1 000 hooks observed) calculated for sets with sharks present, was used to show bathymetric and geographical distributions and biological data were analysed.
  • Secretive Sharks of the Open Ocean. the Marine Biologist, 9, 6

    Secretive Sharks of the Open Ocean. the Marine Biologist, 9, 6

    Secretive sharks of the open ocean Open ocean sharks face an uncertain future, but new research gives hope, says David Sims. Blue shark. © Jeremy Stafford-Deitsch. lue stretched down as far as watched her disappear into the depths, Box 1. Satellite tracking could be seen, illuminated by knowing we’d be tracking her move- Bshifting shafts of down-welling ments for many months to come. light. Gazing down through this drop That was over 10 years ago and in the ocean I’d expected to see since then our project has provided something, but nothing moved across insights into the secret lives of oce- the void, nor had it for hours. A anic sharks (see Box 2). Based at the container ship, like a skyscraper on its Marine Biological Association (MBA), side, churned past us a few miles away. we commenced the Save Our Seas Then from the deep a shape glanced Foundation funded project on blue across the corner of my eye, there and and shortfin mako sharks in 2006 to We use two types of electronic tag to not there at the same time. Coming satellite track their ocean travels. Very track long-distance movements of back into view, a sleek, torpedo shape little was known about them in deep sharks. The first is an Argos transmitter that emits ultra-high frequency radio with a sinuous movement, waters of their oceanic habitats, such as a sleek, torpedo signals when the tag’s antenna breaks well camouflaged against where juvenile and adult oceanic sharks the sea surface. Polar-orbiting satellites shape with a the inky backdrop: it was spend time, how and when they move relay data to ground stations.
  • A Review of the Biology, Ecology and Conservation Status of the Plankton-Feeding Basking Shark Cetorhinus Maximus

    A Review of the Biology, Ecology and Conservation Status of the Plankton-Feeding Basking Shark Cetorhinus Maximus

    Author's personal copy CHAPTER THREE Sieving a Living: A Review of the Biology, Ecology and Conservation Status of the Plankton-Feeding Basking Shark Cetorhinus Maximus David W. Sim, † s* Contents 1. Introduction 172 2. Description of the Species 174 2.1. Taxonomy 174 2.2. Morphology and structure 175 3. Distribution and Habitat 179 3.1. Total area 179 3.2. Habitat associations 179 3.3. Differential distribution 182 3.4. Climate-driven changes 183 4. Bionomics and Life History 183 4.1. Reproduction 183 4.2. Growth and maturity 184 4.3. Food and feeding 186 4.4. Behaviour 189 5. Population 203 5.1. Structure 203 5.2. Abundance and density 207 5.3. Recruitment 208 5.4. Mortality 209 6. Exploitation 209 6.1. Fishing gear and boats 209 6.2. Fishing areas and seasons 209 6.3. Fishing results 209 6.4. Decline in numbers 210 * Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, United Kingdom { Marine Biology and Ecology Research Centre, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom Advances in Marine Biology, Volume 54 # 2008 Elsevier Ltd. ISSN 0065-2881, DOI: 10.1016/S0065-2881(08)00003-5 All rights reserved. 171 Author's personal copy 172 David W. Sims 7. Management and Protection 211 7.1. Management 211 7.2. Protection 212 8. Future Directions 213 Acknowledgements 214 References 214 Abstract The basking shark Cetorhinus maximus is the world’s second largest fish reach- ing lengths up to 12 m and weighing up to 4 tonnes.